On 4/15/24 9:32 PM, Kai-Heng Feng wrote:
> In addition to nearest upstream bridge, driver may want to know if the
> entire hierarchy can be powered off to perform different action.
>
> So walk higher up the hierarchy to find out if any device has valid
> _PR3.
>
> The user will be introduced in next patch.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> ---
Since it has been a while, I was not sure what this series is about.
IMO, it is better to include a cover letter with the summary of your
changes.
> v8:
> - No change.
>
> drivers/pci/pci.c | 16 ++++++++++++++++
> include/linux/pci.h | 2 ++
> 2 files changed, 18 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index e5f243dd4288..7a5662f116b8 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -6225,6 +6225,22 @@ bool pci_pr3_present(struct pci_dev *pdev)
> acpi_has_method(adev->handle, "_PR3");
> }
> EXPORT_SYMBOL_GPL(pci_pr3_present);
> +
> +bool pci_ancestor_pr3_present(struct pci_dev *pdev)
> +{
> + struct pci_dev *parent = pdev;
> +
> + if (acpi_disabled)
> + return false;
> +
> + while ((parent = pci_upstream_bridge(parent))) {
> + if (pci_pr3_present(pdev))
I think it should be "parent" here?
> + return true;
> + }
> +
> + return false;
> +}
> +EXPORT_SYMBOL_GPL(pci_ancestor_pr3_present);
> #endif
>
> /**
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 16493426a04f..cd71ebfd0f89 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -2620,10 +2620,12 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
> void
> pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *));
> bool pci_pr3_present(struct pci_dev *pdev);
> +bool pci_ancestor_pr3_present(struct pci_dev *pdev);
> #else
> static inline struct irq_domain *
> pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
> static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; }
> +static inline bool pci_ancestor_pr3_present(struct pci_dev *pdev) { return false; }
> #endif
>
> #ifdef CONFIG_EEH
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
